ASME 2017 15th International Conference on Fuel Cell Science, Engineering and Technology, FUELCELL 2017, collocated with the ASME 2017 Power Conference Joint with ICOPE 2017, the ASME 2017 11th International Conference on Energy Sustainability, and the ASME 2017 Nuclear Forum
Polymer electrolyte membrane (PEM) fuel cells have been explored as a clean battery replacement in portable and miniature applications where total system mass and specific energy density (Wh/kg) are critical design constraints. By coupling a boost (step-up) DC/DC converter with a miniature PEM fuel cell stack, the total power system mass can be reduced while providing voltage regulation capabilities not available with a fuel cell alone. This configuration is applied to the design of a controlled meteorological (CMET) balloon power system as a casestudy. In this work, we designed and tested three different micropower DC/DC boost converters that were deployed in series with a PEM fuel cell stack. Testing of the converters revealed a transition region in which the converter output voltage is hysteretic, not well regulated, and dependent on the input voltage. As a result, it is important to identify the minimal stable and reliable input voltage to a given DC/DC converter in order to minimize the fuel cell power system mass. An optimization strategy is presented here that enables the minimization of PEM fuel cell stack mass by identifying the appropriate DC/DC converter input voltage subject to the dimension constraints of the fuel cell components. Prototype DC/DC converters were then experimentally tested in direct connection to a miniature two-cell PEM fuel cell stack.
Wei, Yijin and McKahn, Denise A., "Minimization of Stack Mass in Miniature PEM Fuel Cell Systems with DC/DC Converters" (2017). Engineering: Faculty Publications, Smith College, Northampton, MA.